Which type of front is defined as a transition zone between cold and warm air?

The transition zone between cold and warm air is defined primarily as a cold front. A cold front occurs when a mass of cold air pushes into an area occupied by warm air. As the cold air is denser than the warm air, it forces the warm air to rise. This lifting of warm air can lead to cloud formation and precipitation, which are characteristic features of cold fronts. Understanding this process is crucial in meteorology, as it plays a significant role in weather patterns and storm development.

In contrast, a warm front is the boundary where warm air advances towards cold air. Orographic fronts relate to the effects of terrain on weather and do not define a direct transition zone between air masses. A stationary front occurs when neither air mass is advancing and the front remains in place, which does not describe a dynamic transition between different air mass types.